Timepiece barrel with a twisted arbour

Abstract

A twisted arbour barrel ( 1 ), including a barrel drum ( 2 ) provided with a housing, a spring arranged in the housing of the barrel drum ( 2 ), an arbour ( 4 ) at least partially passing through the housing, the spring being compressed by rotation of the arbour in a first direction of rotation ( 12 ), the arbour ( 4 ) being provided with a protruding end ( 9 ) of the drum ( 2 ), a ratchet ( 3 ) arranged on the drum ( 2 ), the ratchet ( 3 ) being configured to allow the rotation of the arbour ( 4 ) in the first direction of rotation ( 12 ), the protruding end ( 9 ) passing through the ratchet ( 3 ) through an opening ( 14 ) cooperating by interlocking with the protruding end ( 9 ), the protruding end ( 9 ) of the arbour ( 4 ) having a twisted shape around its axis.

The invention claimed is: 
     
       1. A twisted arbour barrel comprising:
 a barrel drum provided with a housing, 
 a spring arranged in the housing of the barrel drum, 
 an arbour at least partially passing through the housing, said spring being compressed by rotation of said arbour in a first direction of rotation, the arbour being provided with a protruding end, 
 a ratchet arranged on the drum, the ratchet being configured to allow the rotation of the arbour in the first direction of rotation, the protruding end passing through the ratchet through an opening cooperating by interlocking with the protruding end, 
 wherein said protruding end has a shape twisted around its axis. 
 
     
     
       2. The barrel according to  claim 1 , wherein the protruding end is twisted in the direction opposite to said first direction relative to the drum. 
     
     
       3. The barrel according to  claim 1 , wherein said protruding end is of polygonal section, the opening of the ratchet having a corresponding shape. 
     
     
       4. The barrel according to  claim 3 , wherein said protruding end is of square section. 
     
     
       5. The barrel according to  claim 1 , wherein edges of said protruding end are chamfered. 
     
     
       6. The barrel according to  claim 1 , wherein said protruding end comprises a distal face angularly offset relative to its base on the barrel. 
     
     
       7. The barrel according to  claim 6 , wherein the offset is at least 30 degrees. 
     
     
       8. The barrel according to  claim 1 , further comprising a core surrounding said arbour, the core being arranged in the housing. 
     
     
       9. The barrel according to  claim 8 , wherein the spring is held in the housing, on the one hand, at an internal peripheral face of the barrel, and on the other hand, at the core. 
     
     
       10. The barrel according to  claim 1 , wherein the arbour passes through the housing and is mounted rotationally free relative to said barrel drum. 
     
     
       11. The barrel according to  claim 1 , further comprising a pawl cooperating directly or indirectly with teeth arranged on an outer peripheral face of the drum, so as to prevent the drum from rotating in the direction opposite to the first direction. 
     
     
       12. A horological movement comprising the barrel according to  claim 1 . 
     
     
       13. A timepiece comprising the horological movement according to  claim 12 .